2.5 Operators — Edexcel 4CP0

Arithmetic Operators

Arithmetic operators perform mathematical calculations and always return a numeric result.

Operator	Meaning	Example	Result
+	Addition	7 + 3	10
-	Subtraction	7 - 3	4
*	Multiplication	7 * 3	21
/	Division (real result)	7 / 2	3.5
DIV	Integer division (quotient only, no remainder)	7 DIV 2	3
MOD	Modulo (remainder after integer division)	7 MOD 2	1

SET total TO 17
SET groups TO total DIV 5    # 17 DIV 5 = 3 (full groups)
SET leftover TO total MOD 5  # 17 MOD 5 = 2 (remaining items)
SEND groups TO DISPLAY       # 3
SEND leftover TO DISPLAY     # 2

Relational Operators

Relational operators compare two values and return a Boolean result (TRUE or FALSE). They are used in conditions for IF and WHILE statements.

Operator	Meaning	Example	Result
=	Equal to	5 = 5	TRUE
<>	Not equal to	5 <> 3	TRUE
<	Less than	3 < 7	TRUE
>	Greater than	7 > 3	TRUE
<=	Less than or equal to	5 <= 5	TRUE
>=	Greater than or equal to	4 >= 6	FALSE

Logical Operators

Logical operators combine Boolean conditions. Edexcel 4CP0 requires AND, OR, and NOT only.

Operator	Meaning	Returns TRUE when…
AND	Both conditions must be true	Both left and right sides are TRUE
OR	At least one condition must be true	Either left or right (or both) is TRUE
NOT	Inverts the Boolean value	The condition is FALSE (NOT TRUE = FALSE)

# AND example
IF age >= 16 AND hasID = TRUE THEN
    SEND "Access granted" TO DISPLAY
END IF

# OR example
IF day = "Saturday" OR day = "Sunday" THEN
    SEND "It's the weekend!" TO DISPLAY
END IF

# NOT example
IF NOT isRegistered THEN
    SEND "Please register first" TO DISPLAY
END IF

📝 Exam Tip: MOD is used to check divisibility. If x MOD 2 = 0, then x is even. If x MOD 5 = 0, then x is a multiple of 5. This is a very common exam pattern.

⚠️ Common Mistakes

Confusing / and DIV — / gives a real result (e.g. 3.5), DIV gives the integer quotient only (e.g. 3)
Using = to assign in a condition — in pseudocode = means "equal to" in conditions, not assignment
Using NAND, NOR, or XOR — these are NOT in the Edexcel 4CP0 specification